A woman who noticed small black dots appearing around her home took to the internet to ask for help in identifying what they could be.
Photos show small dots clustered together on top of a computer and on skirting boards, with some of the mystery markings appearing to drip down on the white paint.
Confused over what could be causing it, she shared the images to the Mrs Hinch’s Cleaning Tips Facebook group, asking: "Does anyone have any idea what these marks could be?
"They started appearing on the tiles in the kitchen in random little patches, then this morning this was on the top of the PC we have in the kitchen."
And she was left a little creeped out when plenty of other members informed her that the groupings of black dots looked likely to be spider poo, as reported by The Sun.
One commented to say: "Spider poo. It washes off with no effort."
Another replied: "Defo spider poo - got on door due to light outside."
Animal Hype, a website run by wildlife author and blogger Elise McDonald, states: "Look closely on skirting boards or walls of your house to see if there is anything unusual resembling a paint splatter. If you find any, you are looking at the spider poop.
"Spider droppings, in general, are dark, semi-liquid, and squishy that it resembles a paint splatter. Considering the omnivorous diet of a spider, its poop can have shades of black, brown, white, or grey.
"The best place to look for spider dropping is near their webs that are most commonly found in places away from human contact."
To remove the droppings, it recommends mixing a small amount of bleach with water, leaving the solution on the stained area for 15 minutes before scrubbing away, and repeating if necessary.
